a. Field of Invention
This invention relates to pyrroloisoquinoline derivatives, to intermediates used in their preparation and to methods for preparing and using these compounds.
More specifically, this invention relates to pyrrolo-[4,3,2-de]isoquinolines possessing central nervous system and circulatory system activities. For example, the compounds of this invention show antidepressant and antihypertensive properties in mammals at dose levels which do not elicit undesirable side effects. This combination of attributes render the pyrroloisoquinoline derivatives of the invention useful and desirable as therapeutic agents.
B. Prior Art
Prior interest in the field of pyrroloisoquinolines seems to be practically nonexistent. The only reference to this unusual ring system appears to be a recent chemical paper, D. E. Horning, et al., Can. J. Chem., 49, 2797 (1971), in which the main object of the paper was the preparation of particular 2-substituted 4-indolecarboxylic acids, a 1,3,4,5-tetrahydropyrrolo[4,3,2-de]-isoquinolin-5-one intermediate being isolated in the process.
On the other hand some interest has been shown for the related field of pyrroloquinolines and IH-azepino[4,3,2-cd]indoles. For example, see J. B. Hester, J. Org. Chem. 29, 1158 (1964) and 32, 4095 (1967); see also U.S. Pat. No. 3,330,835, issued July 11, 1967 and U.S. Pat. No. 3,314,942, issued Apr. 18, 1967. However, the compounds of the present invention are distinguished from these prior art compounds by their different ring structure and pharmacologic properties.